Continuous Creation

First, the human race thought it was the pinnacle of creation, and alone, as the only sentient race there's ever been or will be in the universe.

Then there was that awkward moment of culture shock when humanity started to discover the first Spindle artefacts and remains.

Then a new layer peeled off the onion when it was discovered that the Spindles, in their turn, had thought they were alone in the universe and the pinnacle of sentient creation. Then they discovered still earlier Wheeler artefacts and remains. The culture shock was so immense that the Spindles promptly died out.

And before the Wheelers, there were the Paleotechs. Who had discovered a still earlier race, the Ch'Thones.

Who in their turn were building on a universe they had inherited from the RIME.

Kin Arad theorised that there was no such thing as a "natural" universe. Races arise, change the universe to suit themselves, and then die. And then another race emerges from the ruins to take over and re-shape the Universe to its own ends. Sooner or later, something will arise to fill the void left by humanity, once our turn is over...